1. Field of the Invention.
The present invention relates generally to root crop harvesters and more particularly to harvesters utilizing cleaning conveyors of the type having counter-rotating driven rollers disposed adjacent to one another where such rollers employ yieldable mounting means.
2. Description of the Prior Art
In the harvesting of beets or other root crops, the harvesting machine conventionally digs up the beets and deposits them on a conveyor which moves the beets rearwardly and upwardly for deposit on a cleaning conveyor. The cleaning conveyor moves the beets laterally to a vertical auger conveyor which moves the beets upwardly for deposit on yet another conveyor which moves the beets to a deposit area.
The beets have clods of dirt or mud adhering thereto when they are first deposited on the cleaning conveyor. In order to process the beets more efficiently, it is first necessary to separate them from the major portion of the adhering clods. This operation is accomplished on the cleaning conveyor which consists of a series of adjacent counter-rotating rollers which roll the beets and remove the clods from their sides by friction or by impact while conveying them axially of the rollers. Movement of the beets along the cleaning conveyor is accomplished by helical ridges which push the beets lengthwise of the rollers toward the vertical auger as the rollers rotate. In the process, the clods fall through the spaces between the rollers, whereas the much larger beets remain on top of the rollers.
Since rocks occasionally reach the cleaning conveyor surface, it is desirable to make the rollers resiliently separable to a limited degree to prevent jamming of the machanism by rocks which are too small to be conveyed, and yet too large to fall through the spaces between the rollers. Yieldably mounting the rollers to prevent jamming by rocks creates another problem in that dirt and debris tends to build up on the yieldably mounted structure located under the rollers directly below the spaces between the rollers. The build up problem occurs on the vertical auger conveyor end of the cleaning conveyor since the beets pass over the yieldably mounting structure before entering the lower end of the vertical auger conveyor. Dirt and debris falling through the spaces between the rollers builds up on the yieldably mounted structure located under the rollers; blocks the spaces between the rollers; and builds up above the upper surface of the rollers, thus hindering the flow of beets to the vertical auger conveyor. When this buildup occurs, the operator must stop the harvester, open the vertical auger housing, and manually dislodge the buildup with a bar or the like. Such interruptions naturally decrease the operating efficiency of the harvester.
A further problem occurs in the area of the lower end of the vertical auger conveyor in that the helical flighting of the vertical auger repels the beets as they move from the cleaning conveyor into the vertical auger. This problem has lead to the use of a flapper bar located directly above the opening in the vertical auger conveyor housing. The flapper bar extends transversely of the cleaning conveyor and is drivably rotated to contact the beets and force them into the vertical auger. Use of the flapper bar, however, further complicates the structure and maintenance of the harvester.